The Karpeles Manuscript
Library coin archives contain several areas not normally seen by the average
collector.

The first area is Coin
Errors.

These include

Coins that did not fall
directly under the stamping 'dies' and so were stamped "off-center".

Coins that were stamped
twice, once properly and once "off center". These are called "double struck".

Coins where the coin blank
(planchet) fell into the wrong bin and was stamped with a wrong denomination.

Coins whose planchets that
fell on top of a larger coin while being stamped!An example of such an error is shown below, the 1943 Steel Half Dollar.

Would you believe that a planchet can enter between the dies but be balanced on it's edge? And when the dies compress the planchet is "Folded" in half?

One of the most unexpected errors occurs when a small planchet falls between two very large dies, for example a penny planchet into a silver dollar size dies. The penny, being copper, is a different color than the dollar. Here are several "Eisenhower Pennies".

One of the most famous errors is theThe 1943 Copper CentThis one shown is the most fabulous one you will ever see. A 1942 copper penny was struck over by a 1943 nickel.(All others are a 1942 blank planchet struck over by a 1943 die intended for a steel cent)
The 1943 Steel Half DollarThe second most fabulous 1943 coin you will ever see. A1943 steel planchet fell into the half dollar stamping area. The strike is amazingly also off center.
The 1943 Steel Cent PatternNot an error coin but a trial pattern made in 1942 at the U.S. Mint in the proposed metal (steel coated by zink) for the 1943 cents. It is shown here to go along with the 1943 cent errors listed above.

The second area is
Kushan Coins.

Kushan was a country part way
between Rome and China. It served as a rest stop for traders traveling between
the two countries. The Romans spent many gold coins in Kushan - and when it's
ruler, Vima Kadphises, saw these gold coins he was amazed at the quality of the
engravings. The portraits of the Roman Emperors on the coins were astoundingly
photographic - equal to the 21st century United States Mint coins.
Vima decided to make his own coins by melting down the Roman coins and creating
stamping dies with Kushan portraits and designs. In particular, Vima's
successors, Kanishka and Huvishka,started a series where world gods would adorn the verso of many of the
coins:

The composition of the
coins used which have portraits of Cleopatra were not as good as the normal
Roman coins. Thus, coins with distinct portraits of Cleopatra very hard to
find. Here are the best available:

The fifth area is coins of Denmark during the period when the Kings of Denmark were also Kings of England.

The Viking Age (800 AD-1100 AD) was a period of attempted conquests of England by Viking Denmark. King Aethelred of England was forced to pay 'tribute' to Danish leaders in order to avoid conquest. This was the time of Leif Erickson discovery of America. Aethelred massacred Danish settlers in 1002, setting the stage for the Danish conquest of England.
King Sweyn, conquered England in 1013 and became King of England and Denmark (and Norway). Sweyn's son, Canute the Great, who reigned from 1014 to 1035, united Denmark and England stressing cultural bonds. His son, Harthacnut was not so kind. He ruled until 1042 AD but under a policy of harsh taxation.
Lady Godiva, an Anglo-Saxon noblewoman, rode naked through the streets of Coventry, in England, in order to gain a remission of Harthacnut's oppressive taxation policy imposed by her husband on his tenants.Danish Coins when the Kings of Denmark were also Kings of England